<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <link href="lib/twitter-bootstrap/css/bootstrap.css" rel="stylesheet">
</head>

<body>

    <div class="container">
        <form   >
            <!--col-xx-xx：栅格数  m-auto：居中-->
            <!--m-x：边距  mt-x：上边距  mb：底边距  mx：左边距  me：右边距-->
            <!--row：容器内元素水平排列-->
            <div class="mb-3">
                <label class="form-label">Email address</label>
                <input class="form-control">
                <div class="form-text">We'll never share your email with anyone else.</div>
            </div>
            <div class="mb-3">
                <label class="form-label">Password</label>
                <input class="form-control">
            </div>
            <div class="mb-3 form-check">
                <input class="form-check-input">
                <label class="form-check-label">Check me out</label>
            </div>
            <button type="submit" class="btn btn-primary">Submit</button>
    </div>



    <div class="container mt-5">
        <div class="row g-3 col-7 m-auto">
            <!--g-x：容器内div下边距-->
            <div class="col-md-6">
                <label class="form-label">Email</label>
                <input class="form-control">
            </div>
            <div class="col-md-6">
                <label class="form-label">Password</label>
                <input class="form-control">
            </div>
            <div class="col-12">
                <label class="form-label">Address</label>
                <input class="form-control" placeholder="1234 Main St">
            </div>
            <div class="col-12">
                <label class="form-label">Address 2</label>
                <input class="form-control" placeholder="Apartment, studio, or floor">
            </div>
            <div class="col-md-6">
                <label class="form-label">City</label>
                <input class="form-control">
            </div>
            <div class="col-md-4">
                <label class="form-label">State</label>
                <select class="form-select">
                    <option selected>Choose...</option>
                    <option>...</option>
                </select>
            </div>
            <div class="col-md-2">
                <label class="form-label">Zip</label>
                <input class="form-control">
            </div>
            <div class="col-12">
                <div class="form-check">
                    <input class="form-check-input">
                    <label class="form-check-label">
                        Check me out
                    </label>
                </div>
            </div>
            <div class="col-12">
                <button type="submit" class="btn btn-primary">Sign in</button>
            </div>
        </div>
    </div>


    <script src="lib/jquery/jquery.js"></script>
    <script src="lib/twitter-bootstrap/js/bootstrap.js"></script>
</body>

</html>